<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Tenplate</title>
</head>
<body>

<div id="app">
    <!-- 不加引号是使用data中的数据变量 -->
    <h2 class="title" :class="[active, 'line']">{{message}}</h2>
    <h2 class="title" :class="getclass()">{{message}}</h2>
</div>

<script src="../js/vue.js"></script>
<script>
    const app = new Vue
    (
        {
            el : "#app",
            data : 
            {
                message : "hello",
                active : "aaaa",
                line : "bbbb",
            },
            methods :
            {
                getclass : function ()
                {
                    return [this.active, this.line];
                },
            }
        }
    )
</script>
    
</body>
</html>